Side-haul railway dry dock



March 25, 1952 J, CRANDALL 2,590,689

SIDE-HAUL RAILWAY DRY DOCK Filed Feb. 5, 1949 3 Sheets-Sheet 1 March 25, 1952 J. 5. CRANDALL 2,590,639

SIDE-HAUL RAILWAY DRY nocx Filed Feb. 5, 1949 s Sheets-Sheet 2 3 2 I 1; l 50$ 5 a 30 Ja j; i2 /1 1 11 March 25, 1 J. 5. CRANDALL 2,590,689

SIDE-HAUL RAILWAY DRY DOCK Filed Feb. 6, 1949 s Sheets-Sheet 5 r Y jig-9.

Patented Mar. 25, 1952 SIDE-HAUL RAILWAY DRY DOCK James Stuart Crandall, Lexington, Mass, assignor to Crandall Dry Dock Engineers 1110., Cambridge Mass accrporation of Massachusetts Application February a, 1949, Serial Nb. 74,278

3 Claims.

This invention relates to improvements in cradle frames for side haul railway dry docks.

More particularly it provides an improved unitary side haul frame which is adapted to cradle'a ship or hull for broadside-movement along tracks ofa railway dry docking facility under the control of hauling cables or chains connected tothe cradle at only two points alon the length of the cradle.

Side haul railway dry docking facilities ordinarily includea series of inclined parallel tracks suitably supported with their lower endsv immersed to asubstantial depth in a body of Water from and to which ships or hulls are to be moved broadside along the inclined tracks to and from an elevated location at which. the shipor hull may be supported while work is performed thereon, or the said elevated location may be a transfer location, in which-case horizontal tracks maybe'disposed on land and lead to thetransfer location to facilitate movements of a ship or-hu11 along the horizontal tracks to or from the transfer location.

Heretofore, it has been usual practice to provide a wheeled cradle on each pair of inclined tracks of the, side haul railway dry docking facility and to-support-a ship or hull arranged across-all of the series of cradles. Each individual cradle has required its own hauling chain or cable and it has been impossible to predetermine the magnitude of the load required to be borne by any particular chain or cable. The approximate total load in most cases may be predetermined, but therehas been no way of even approximating-in advance the magnitude of the load to be imposed on-any-particular cradle and-on the' individual hauling-chains-or cables. The result has been that some" hauling elements becomeseriously over-loaded, with frequent snapping of overloaded elements, while other hauling elements carry grossly less than-their proportional shares of the totalload and, short of actual rupture of over-loadedhauling elements, they not infrequently become stretched with resulting overstressing and possible distortion of the hull or vessel which is being handled.

.Whilevarious load equalizing proposals are available, designed to distrib ute a load equally among multiplezhauling cables; none. f, them: s far as Lam-aware, has. been effectively useable for-side haul cradle frames because thecenter ofgravity of the load seldom, if ever, will coincide, with the center of the multiplicity of haulingelements, making it mechanically impossible to distribute the load equally among the numercusihaulin elements.

It is amongthe objectsofthe present inventionto providea unitary side haul cradle frame having only two points of connection of hauling chains or cables, the two said points of connection being at opposite ends of a zone or region predetermined as a locus within which will lie the center of gravity of any load which it is contemplated that the cradle may be required to carry, whereby the maximum load which can be placed on the hauling element or elements at each said point of connectionmay be predetermined and thesaid hauling element-or elementsat each point of connection made capable of carrying the said maximum load.

Another object is to provide aunitary cradle frame for side haul railway dry docksv wherein a series of parallel wheel-carrying elements are rigidly connected together for wheeled support of the cradle on a series of inclined parallel tracks, and wherein the extremities of a predetermined locus of centers of gravity of different loads to be carried by the cradle determine the 7 locations of two points of connection of hauling elements to the cradle, at which points all of the hauling elements for the cradle are equally distributed.

It is, moreover, my purposeand object generally to improve upon prior side haul cradle frames, and prior side hauling procedures, in the art of railway dry docks, and the like.

In the accompanying drawings:

Fig. 1 ise plan view of a railway dry dock including -a unitaryjside haul cradling frame which embodies features of the invention;

Fig. 2 isa cross sectional view approximately cn'line -20 Fi 1;

Fig.3 is a somewhat diagrammatic top plan View of the side haul cradle'frame of Figs. land 2, the right hand end portion having the upper structure broken away;

Fig. d isa cross-sectional view approximatelyon line. 4.4 of Fig. 1, showing a hull on the cradle;

7 Fig. 5 is an, end elevation of the cradle on, a larger scale;

Fig. 6 is a cross-sectional view on line;6 -6 of Fist 3 n 5;

,Fig. '7 is, a cross-sectional viewon line 1-! of Figs. 3 and 5,011 a lar er. scale;

Fig. 8 is a cross-sectional view on line .8 98 of Figs. 3 and 5; and

Fig.9 is.-a fragmentary cross-sectional view on line 9-9 of Fig. 5, on alarger scale.

Referring to the drawings, and more particu- 1arly to Figs. 1 and 2 thereof, the inclined ways of aside haul railway dry dock are indicated generally at l0, six ways being represented in Fig. 1, and each way including a pair of parallel inclined tracks H. As best seen in Fig. 2, the ways and tracks extend from well down in a body of water 14 to locations substantially above the water level and distributed along the shore or bank [6 at a transfer location indicated generally at H, from which transfer location horizontal transfer tracks iii are shown extending on land to facilitate broadside movements of a ship or hull to and from the transfer location. However, it is not unusual to find a side haul railway dry dock having no transfer tracks on land, in which case the location herein designated as the transfer location may be the resting place for a ship or hull while work is being performed there on. Hence, the transfer tracks I3 constitute no essential part of the invention.

According to the invention, a unitary side haul cradle 20 is mounted across all of the ways If), the cradle being equipped with a multiplicity of wheels 22 on its under structure whereby the cradle may be moved broadside up and down the ways I 0, with a plurality of wheels 22 engaging each inclined track i I at different locations along each track.

Cradle 20 is herein illustrated as of structural steel frame construction having the generally triangular cross-sectional shape as seen in Figs. 2 and 5. It has pairs of parallel and inclined channel beams 24 (Figs. and 7) supported at the lower ends of vertical I-beams 26 of varying lengths which are spaced substantially apart along the channel beams 24, the I-beams 25 having their lower ends engaged between the channel beams of each pair whereby space is provided between the channel beams within which the wheels 22 may rotate, the wheels being secured to the channel beams 26 as best seen in Figs. 5 and 7. The vertical I-beams 26 have gradually decreasing length from one side of the cradle to the other, with their upper ends all in a common horizontal plane, whereby their lower ends are positioned to support the channel beams 24 in an inclined plane which will be predetermined to correspond with the inclination of the inclined tracks II on the ways In, and the number of wheel-carrying pairs of channel beams 24 will correspond with the number of tracks H which are provided on the ways It).

The upper ends of the vertical I-beams 28 in each transverse row are rigidly connected together by the horizontal angle bars 36 which extend transversely of the cradle at opposite sides of each row of I-beams 26, as best seen in Figs. 5 and 7, and these same angle bars 3'6 in conjunction with the upper ends of the I-beams 25, support the longitudinal I-beams 28 which are suitably secured thereto. The longitudinal I-beams 28, in turn, support the transverse transfer tracks 30 which are secured to the I-beams 28 and arranged for registration with the transfer tracks I 8 on land when the cradle is at the transfer location in which it is represented in Figs. 1 and 2.

Preferably, the cradle is further strengthened by the vertical channel beams 32 whose lower ends are secured between the inclined pairs of channel beams 24 and whose upper ends are secured to relatively short longitudinal channel sections 34 as best seen in Fig. 8. These short channel sections 34 are located between adjacent longitudinal I-beams 28, providing added support for each pair of tracks. As shown in Fig. 8, the upper portions of the vertical channel beams 32 extend between the angle bars 38 and the bars 36 are secured to channel beams 32 as well as to the I-beams 28. Also, at the smaller end of the cross-section of the cradle, as seen in Figs. 5 and 6, relatively short channel sections 38 support the end portions of the transfer tracks on the end portions of the inclined channel beams 24, all of whose ends are connected together longitudinally by the I-beam 40, at the smaller end of the cross-section and by the I-beam 42 at the larger end of the cross-section.

Referring now to the right hand portion of Fig. 3 and the fragmentary sectional plan view of Fig. 9, it will be seen that in addition to the longitudinal I-beams 40, 42 which extend along the opposite side extremities of the lower structure of the cradle, a comparable longitudinal I-beam 44 extends in the common plane of beams 46, 42 at a location centrally between beams 40, 42, and a system of truss-work braces the under structure in a manner to effectively distribute hauling forces applied by a chain 46 throughout one-half the length of the cradle, the other half of the lower structure being similarly trussed to dis tribute forces applied by the other chain 46 throughout that half of the structure. As represented, channel bars 48 extend diagonally from corner to corner of each of the rectangles defined by the I-beams 40, 42, 44 and the channel beams 24, excepting that rectangle immediately adjacent to the connection of chain 48, this rectangle having two angle bars 50 converging at the point of connection of chain 46 from the two more remote corners of the rectangle. Also, the rectangle adjacent to the one having the converging bars 50, and in line with the chain 43. and the two rectangles centrally between the ends of the cradle, have crossing channel bars 48 extending diagonally to and from each of their corners.

Inasmuch as the chains 46 are attached to the longitudinal I-beam 40, the hauling stresses are applied to and effectively distributed over the under structure and through the vertical beams 26, 32 to the upper structure. lower and upper structures will be further trussed for constituting a rigid unit by diagonal brace bars 52 in line with the chains 46 at central regions across the width of the cradle and at the side remote from the chain connections.

In operation, my unitary cradle, mounted on the inclined tracks Ii, may be moved up and down the inclined tracks under the control of hauling chains 46 connected at only two pre a hull to and from the cradle in cases where the dry dock has transfer tracks IS on land. But, in contrast with prior side haul procedures requiring a separate cradle for each pair of inclined tracks, with the accompanying need for.

multiple hauling cables for the multiplicity of cradles, I provide a unitary cradle structure wherein the hauling stresses are applied at only two points on the cradle. The two connection points on the cradle are located so as always to be on opposite sides of the center of gravity of Preferably, the I each of the connection points, eliminating guesswork and; avoidin the annoyance and expense incident to rupture of hauling elements in the prior side hauling procedures.

While the drawings illustrate inclined railway tracks H, which are straight, curved or bowed tracks sometimes are employed, with either con vex or concave curvature. My improved unitary side haul cradle, designed for operation on such curved track railways obviously would have its wheel-carrying under structure formed with curvature"complementing the track curvature. Also, the showing of a single chain 46 at each of the two "connection points on the cradle should be regarded as illustrative of hauling elements in general; and it will be obvious that one, two or more chains, cables, etc., may be connected at each of-the two connection points, the essential requirement being that the pull be applied at only the two connection points.

It is intended that the patent shall cover, by suitable ekpression in the appended claims, whatever features of patenta'ole novelty exist in the invention disclosed.

I claimfas my invention:

1. In a side-haul railway dry dock havingi o. series ofparallel inclined tracks leading from below the. surface oi a body of water to a location above the surface of the water, a long unitary cradle. disposed across and supported by all of said inclined tracks, said cradle comprising a base structure and a deck structure supported on the base structure, said base structure having spaced and generally parallel rigid longitudinal eleinents'cxtending throughout the length of the cradle ina plane adjacent and parallel to the inclined plane of generallyparallel rigid transverse elements. extending throughout the width oi the cradle in the general plane of and rigidly connected to said longitudinal elements, said deck structure having spaced generally parallel rigid longitudinal elements extending substantially throughout the length of the cradle and in a plane above and at an. acute angle to the plane of the base structure, and spaced generally parallel "rigid transverse elements rigidly connected to said longitudinal elements of the deck structurefantifriction means acting between each said inclined track and a said transverse element of the base structureat distributed locations along each said track, rigid struts extending between the transverse elements of the base and deck structuressaid tracks, and spaced and a se -089' the base structure against relative movement in their inclined plane under loadstresses imposed series of parallel inclined tracks leading-from below thesurface of a body of water to a location above the surface of the water, a long unitary cradle disposed across and supported by all of said inclined tracks, said cradle comprising a base structure and a deck structure supported on the base structure, said base structure having spaced and generally parallel rigid longitudinal elements extending throughout the length of the cradle in a plane adjacent and parallel to the inclined plane of said tracks, and spaced and generally parallel rigid transverse. elements extending throughout the width ofthe cradle in the general plane of and rigidly connected to said longitudinal elements, said deck structure having spaced generally parallel rigid longitudinal elements extending substantially throughout the length of the cradle substantially in a horizontal plane above said base structure, and spaced generally parallel rigid transverse elements rigidly connected to said longitudinal elements of the deck structure, transverse generally horizontal parallel tracks on the deck structure extending "at one side of the cradle into relatively close relation to the underlyin side margin of said base structure, rigid longitudinal means rigidly connecting said base structure and said deck tracks together along said one side of the cradle, antifriction means acting between each said inclined track and an adjacent transverse element of the base structure at distributed locations along each said inclined track, rigidstruts extending between said transverse elements of the base and deck structures at a series of spaced locations across the width of the cradleflor supporting the deck structure in its said plane above the base structure, trussing means operative between said longitudinal and transverse elements of the cradle maintaining all of said transverse elements of the base structure against relative movement in their inclined plane under load stresses imposed on the cradle when the cradle, with a hull on its deck structure, is moved along said inclined tracks, and tensile hauling elements connected to said cradle at only two separated points between the ends of the cradle at that side of the cradle along which said base structure and deck tracks are rigidly secured together.

3. A side-haul cradle. having a generally horizontal deck structure forsupporting a hull disposed lengthwise thereon and having a base structure disposed in an inclined plane generally parallel to the plane of inclined railway tracks along which the cradle is adapted to move, said base structure having a rigid transverse element adjacentand parallel with each inclined railway track for coaction with anti-fricticn means adapted to act between said transverse elements and the inclined tracks when said cradle is disposed across a series of the inclined tracks for broadside movements therealong, rigid means connecting said base and deck structures together including trussing elements operative to maintain said transverse elements of the base structure against relative movement in their inclined plane under load stresses imposed on the cradle when the cradle, with a hull thereon, is drawn broad- 7 side up the inclined railway tracks, andtensile hauling elementsconnected to the cradle at only two spaced points between the ends of the cradle for hauling the cradle and its load up the inelined tracks with each track constantly supporting itsshare of the load regardless of whether the load is equally divided between the tensile hauling elements at each of said two points of connection to the cradle.

v JAMES STUART .CRANDALL.

REFERENCES CITED The following references are of record in th file of this patent:

Number UNITED STATES PATENTS Name 'Date Thompson Aug; 20, 1872 Smith June 17, 1890 Beebe July 20, 1897 Dravo May 24,1932 FOREIGN PATENTS Country Date Great Britain 1928 

